Device for centering a metal bar entering the gap between two adjustable sizing rolls



y 1970 R. SCHQFFMANN 3,512,389

DEVICE FOR CENTERING A METAL BAR ENTERING THE GAP BETWEEN TWO ADJUSTABLE SIZING ROLLS Filed June 16. 1967 3 Sheets-Sheet 1 FIG./

INVENTOR RUDOLF SCHOFFMANN HIS ATTORN EYS y 1970 R. SCHGFFMANN 3,512,339

DEVICE FOR CENTERING A METAL BAR ENTERING THE GAP BETWEEN Two ADJUSTABLE SIZING ROLLS Filed June 16. 1967 3 Sheets-Sheet 2 FIG. 2

INVENTOR RUDOLF SCHOFFMANN BY fl w/ 4, Li; TM

HIS ATTORN EYS May 19, 1970 SCHOFFNIANN- DEVICE FOR CENTERING A METAL BAR ENTERING THE GAP BETWEEN TWO ADJUSTABLE SIZING ROLLS Filed June 16. 1967 3 Sheets-Sheet 3 INVENTOR RUDOLF SCHOFFMANN BY MEMZWWM Has ATTORNEYS United States Patent O US. Cl. 72-250 1 Claim ABSTRACT OF THE DISCLOSURE Centering apparatus for a rolling mill is described. A pair of centering shoes are disposed one on either side of the path of the metal bar adjacent the rolls. One

or both of the centering shoes includes a piston portion sildable within a cylinder upon application of hydraulic pressure, the shoe position relative to the path of the bar thus being hydraulically controlled. A stop within the cylinder limits the maximum displacement of the shoe toward the path of the bar and spring bias means within the cylinder returns the shoe to an initial withdrawn position upon release of hydraulic pressure.

The invention relates to a device for centering a metal bar on entering the gap between two adjustable sizing rolls.

In the operation of continuous casting plants, namely when reducing the bar to a small crosssection, difiiculties arise when the unshaped head of the bar, which has a still liquid core, passes the rolling mill with the rolling gap wide open, and when subsequently the rolls are screwed down to the desired cross-section. It is necessary to center the bar to the middle axis of the roll caliber, as otherwise an accurate shaping is not possible.

According to the invention, this problem is solved by providing at least two centering shoes arranged on roll gap level on opposite sides of the bar, which center the bar in the direction of the roll axes, at least one centering shoe being adjustable. These centering shoes are preferably arranged in front of the roll gap. Alternatively, they may be provided immediately behind the roll gap. Suitably, the centering shoes are hydraulically operable. Further, it is of advantage to provide stops for limiting the path of the centering shoes.

The subject-matter of invention is illustrated in the drawing by way of two embodiments. FIG. 1 is a vertical cross-sectional view of a charging funnel arranged in front of a rolling mill having one pair of rolls. FIG. 2

ice

shows a cross-sectional view along line II-II of FIG. 1, and FIG. 3 the same sectional view as shown in FIG. 2, but of a modified embodiment.

The charging funnel 30 is suspended on bearing bolts 6, 6; it has a conical inlet 31 narrowing to square shape. The charging funnel 30 is arranged in front of a pair of rolls, the lower roll of which is designated by numeral 8 in FIG. 2. On both sides of the bar 32, centering shoes 33, 33 are provided in the charging funnel, which (in the embodiment shown) are movable by a hydraulic cylinder 34 in the direction of the roll axes, as demonstrated by the arrow. The cylinder has an inlet 35 for a hydraulic medium, which impinges on the centering shoe 33 designed as a piston and presses it in the direction of the arrow. When the hydraulic mechanism is shut off, the re-adjustment spring 36 pulls the centering shoe 33 back into the initial position. Numberal 37 denotes a stop for limiting the path of the centering shoe 33.

The modified embodiment according to FIG. 3 diflers from the one shown in FIG. 2 in that one of the centering shoes is fixedly arranged, i.e. unadjustable, while the opposite shoe 33 is designed in the same way as already described in connection with FIGS. 1 and 2.

What I claim is:

1. Apparatus for centering a metal bar having an unshaped head while entering a rolling mill, said mill having at least one pair of adjustable sizing rolls enclosing a roll gap, said roll gap being opened to accommodate said unshaped head during passage thereof through said rolls and closed thereafter to define the roll caliber, said centering apparatus comprising, a pair of centering shoes operable with said roll gap wide open to center said bar relative to the middle axis of said roll caliber, said shoes being disposed immediately adjacent said roll gap and on opposite sides of the path of said bar, each of said centering shoes being adjustable by a member moving perpendicularly to said path, said member comprising a piston movable within a cylinder upon application of hydraulic pressure, stop means for limiting the extent of movement of said member toward said path, and means for returning said member to an initial position upon release of hydraulic pressure.

References Cited UNITED STATES PATENTS 3,204,441 9/ 1965 Lyle 72-31 3,104,566 9/1963 Schurr et al. 72-8 2,816,467 12/ 1957 Thoren 72-250 1,804,947 5/ 1931 Palmgren 72-250 1,398,843 11/1921 Cullen 72-250 MILTON S. MEI-IR, Primary Examiner 

